Prefabricated reinforced concrete panel curtain-wall system

ABSTRACT

A prefabricated curtain-wall system comprises an assembly of reinforced concrete panels. The reinforcement of the concrete is provided by a grid of horizontal and vertical metal rods, tied together where they cross. Connection between two adjacent panels utilizes an external bracket with two bolts, each bolt mating with a nut protruding from a slotted bracket embedded in each of two adjacent panels The embedded brackets have eyelets for passage of a rod of the reinforcing grid. The lowermost panels of the system are anchored to the building foundation, thus the load of the entire curtain wall system and the embedded reinforcing grid can be transmitted to the foundation. The system incorporates means of adjusting the fitting together of panels to compensate for minor deviations in the dimensions and elevations of construction elements.

This application claims the benefit of a provisional application, Ser. No. 61/283,585, filed Dec. 7, 2009.

FIELD OF THE INVENTION

The present invention relates to the building construction industry, and more particularly to the construction of unitized curtain walls for cladding a building skeleton framework.

BACKGROUND OF THE INVENTION

The development of skeleton framework structural support for buildings in the late nineteenth century created the field of non-load-bearing curtain wall systems, and particularly unitized curtain wall systems. Unitized curtain walls entail factory fabrication and assembly of panels and may include factory glazing. These completed units are hung on the building structure to form the building enclosure. Many early examples of curtain walls involved glass or stone panels framed by mullions. Of late, unitized curtain wall, comprised of composite factory-made panels, has the advantages of: speed; lower field installation costs; and quality control within an interior climate controlled environment. The economic benefits are typically realized on large projects or in areas of high field labor rates. The prior art includes a variety of complex fastening and support systems used to connect such panels together. A common system for connecting panels involves the use of pegs or clips that extend outward from inside an edge of an upper panel, for mating with notches in the panel immediately beneath. This type of system requires great precision in the placement of pins and notches so that they will mate, which may be thwarted in the field where adjustments may be required. This system also concentrates the load of a panel into the notches below, which could break under the stress. One such system is disclosed in U.S. Pat. No. 5,067,300 to Takeda.

U.S. Pat. No. 7,810,288 to Lechasseur attempts to address these issues with a cladding system comprised of flanged panels attachable to the supporting structure, leaving gaps between the panels which are then filled with deformable mouldings. A panel of this system includes a pre-finished exterior sheet of material such as aluminum and a core of trusses, ribs or honey comb structure. Mounting the panels on the supporting structure involves specially designed mounting clips, furring strips, furring attachment flanges, furring spacing segments, special corner mouldings, moulding legs, forks insertable into the panel cores, and overall is rather complicated.

U.S. Pat. No. 6,098,364 to Liu teaches adjustable connections of cladding panels to the supporting building structure. All of the load of the panels is transmitted to the building framework through the adjustable connections The prefabricated panels comprise two layers of “any material” (sic), joined with silicone adhesive. It can be inferred that only materials with some tensile strength could be used in this system, such as fiberglass, which is relatively expensive.

Accordingly it is an object of this invention to utilize prefabricated panels made of reinforced concrete, which is very strong, relatively inexpensive compared to glass, stone, metal or fiberglass, and does not involve mullions. Another object is to provide for simple, adjustable connection means between adjacent panels and to the concrete foundation of the building structure. A further object of the invention is to provide a panel system the load of which is borne by the foundation. Still another object is to tie together the reinforcing rods of each panel to adjacent panels and to anchor the entire cage of reinforcing rods to the foundation. Yet another object is to means of adjusting the fit of panels together to compensate for minor deviations in the dimensions and elevations of construction elements.

SUMMARY OF THE INVENTION

The present invention is a prefabricated curtain-wall system made of reinforced concrete panels. The reinforced concrete is comprised of a grid of horizontal and vertical rods, tied together where they meet. Connection between two adjacent panels utilizes an external bracket with two bolts, each bolt mating with a nut protruding from a slotted bracket embedded in each of two adjacent panels. The embedded brackets have eyelets for passage of a rod of the reinforcing grid. The lowermost panels of the system are anchored to the building foundation, thus the load of the entire curtain wall and the embedded reinforcing can be transmitted to the foundation. Further, this system allows for field adjustment of panels, both vertically and horizontally, to compensate for inconsistencies in foundation heights and plumbness of building skeletons.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a depiction of a prefabricated concrete curtain-wall panel of this invention to the foundation, vertical reinforcing steel rod embedded in the panel, connection of the panel to an upper level panel, and connection to a structural column of a building skeleton.

FIG. 2 is a detailed view of anchoring hardware connecting two adjacent panels in side=by-side relationship.

FIG. 3 is a detailed view of anchoring hardware used to connect two panels on the same level at a right angle to form a corner;

FIG. 4 is a cutaway internal elevational view of the panels of this invention connected side by side and stacked upper level to lower level, and depicting the grid of embedded reinforcing bar and connecting hardware in each panel;

FIG. 5 is a detail view of recessed anchoring hardware for fastening a panel of this invention to a structural column of a building skeleton, such as an I-beam;

FIG. 6 is detail view of connecting hardware between a lower level panel and an upper level panel of this invention;

FIG. 7 is a detail view of a slotted anchor bracket with eyelet for reinforcing bar, part of the anchoring hardware shown in FIG. 5;

FIG. 8 is a perspective detail of a coupling nut shown in FIG. 5;

FIG. 9 is a detail of a special winged fastener designed to fit in the slot of the bracket shown in FIG. 7;

FIG. 10 is a detail of an upper level angle bracket, part of the anchoring hardware indicated in FIG. 1;

FIG. 11 is a detail view of a lower level angle bracket designed to mate with the upper angle bracket;

FIG. 12 is a detail view of an angle bracket for securing panels together at corners;

FIG. 13 is a detail view of a winged fastener designed for use with angle brackets;

FIG. 14 is a detail view of a slotted plate used to secure panels side by side as shown in FIG. 4;

FIG. 15 is a perspective detail view of an anchoring bracket.

DETAILED DESCRIPTION OF THE DRAWINGS

With reference to the drawings, a detailed description of the best mode and preferred embodiment of the present invention ensues, with the understanding that the disclosed embodiment is merely one example of the invention which could be embodied in additional forms. Therefore, specific structure and functional details disclosed herein should not be interpreted as limiting, but solely as a basis for the claims and as a representative basis for teaching someone skilled in the art to variously employ the present invention in an appropriate structure.

In general the invention comprises a pre-fabricated planar concrete panel 1, having internal embedded grids of reinforcing steel rods 6 and embedded anchoring hardware, and an assembly of such panels 1 to form a curtain wall system as the exterior of a steel-framed building, including a multi-story building. As seen in FIG. 1, panels 1 are erected vertically on a reinforced concrete foundation 15 with a concrete anchor bolt 8 securing an angle bracket 7 shown in detail in FIG. 12. Angle bracket 7 is secured to tabbed bracket 3, embedded in panel 1, by special wing nut 5, shown in detail in FIG. 13. As seen in FIGS. 2 and 15, embedded tabbed brackets 3 have eyelets through which embedded reinforcing rods 6 extend.

The embedded vertical and horizontal reinforcing steel rods 6 are secured into a fixed grid, as shown in FIG. 4 Vertical rod 6 passes through an eyelet in embedded bracket 10, shown in FIGS. 1 and 7. As seen in FIGS. 5 and 9, after the panels 1 are bolted to the foundation 15, special winged anchor nut 11 is inserted in the elongated slot of bracket 10 and a coupler nut 25 is use to secure anchor nut 11 to bracket 10, as shown in FIG. 5. The assembly of bracket 10, anchor nut 11 and coupler 25 provides a means of attachment to the structural steel column 22, which will be more fully described later.

Near the top of panel 1, embedded vertical reinforcing rods 6 pass through another embedded bracket 3. FIG. 15 shows bracket 3 with a horizontal slot. The adjoining panel 1 should have an embedded bracket 3 with a vertical slot. FIG. 2 depicts the connection means between two adjacent panels 1 at the same level As shown in FIG. 14, connecting plate 2 has a vertical slot and a horizontal slot. Winged anchor nuts 5 with square shoulders 13, shown in FIG. 13, fit into the slots of brackets 3. Then bolts 4 secure connecting plates 2 to the anchor nuts 5, vertical slots opposing horizontal slots, thereby allowing a degree of tolerance for adjusting the fitting together of the panels 1.

Connecting stacked lower and upper and lower panels 1 involves 2 should be panels 1 involves fastening embedded angle bracket 16 to angle brackets 17 with ordinary bolts 4 and hex nuts 20, again mating a horizontal slot with a vertical slot to allow tolerance for adjusting the fit. Running the embedded grid of steel reinforcing rods through all embedded anchoring hardware ensures the integrity of the assembly of panels 1.

To fasten panels 1 to the steel skeleton of a building, a threaded steel rod 18 is screwed into special wing fastener 11. 

1. A prefabricated curtain-wall system for cladding a building skeleton framework mounted on a concrete foundation, said curtain-wall system comprising an assembly of rectangular, adjacent concrete panels, each panel comprising an outer face, an inner face, opposing side edges, a top edge, a bottom edge and an inner body; an embedded grid of horizontal and vertical reinforcing rods, tied together; a plurality of connecting hardware components, comprised of embedded female members mating with external male members, the male members extending between two adjacent panels, thereby coupling panels (a) in side-by-side relationship, and (b) in stacked configuration with the lowest level panels attached to said foundation, wherein said bottom horizontal edge of an upper-level panel is contiguous to said top horizontal edge of a lower-level panel, wherein each embedded female member is proximal to a side edge, and wherein all couplings and matings are adjustable; means for connecting said grid to said connecting hardware components; adjustable mounting means for attaching the lowest level panels to said foundation. paired male and female components for connecting each said panel in adjustable spaced apart relationship to said framework, each said female component embedded in a panel and each male component mounted on said framework;
 2. The curtain-wall system according to claim 1, wherein each embedded female member comprises a bracket fitted with: (a) a female connector extending outward from, and (b) tabs having orifices extending into, said inner body, from said inner face, said orifices being passages for said reinforcing rods; and wherein each external male member comprises a bracket fitted with a male connector mating with a female connector of an adjacent panel
 3. The curtain-wall system according to claim 2, wherein each said bracket has a slot in which one said connector is movably mounted, whereby two degrees of freedom are provided to achieve optimum alignment of adjoining panels
 4. The curtain-wall system according to claim 3 wherein a bracket for a female connector has an horizontal slot and the male connector mating therewith is mounted in a vertical slot; alternatively, the bracket for a female connector has a vertical slot and the male connector mating therewith is mounted in an horizontal slot.
 5. The curtain-wall system according to claim 4 wherein said mounting means to the foundation comprises external slotted angle brackets, each with a vertical arm and an horizontal arm, the vertical arm coupled to an embedded female member proximal to the bottom edge of a lowermost panel and the horizontal arm affixed to the foundation with a threaded concrete anchor bolt.
 6. The curtain-wall system according to claim 1 further comprising: a similar panel for coupling to an adjacent panel at an angle less than 180° to form a vertical corner, wherein said external male member is comprised of an angle bracket, and said embedded female member is spaced from one said side edge so as to permit the inner face of the similar panel to overlap the adjacent side edge of the adjacent panel.
 7. The curtain-wall system according to claim 6 wherein external hardware components extend from the inner faces of said panels, so that said outer faces of the assembly of panels present a smooth, continuous exterior curtain-wall surface over the building skeleton.
 8. A prefabricated curtain-wall system for cladding a building skeleton framework mounted on a concrete foundation, said curtain-wall system comprising an assembly of rectangular, adjacent concrete panels, each panel comprising an outer face, an inner face, opposing side edges, a top edge, a bottom edge and an inner body; an embedded grid of horizontal and vertical reinforcing rods; a plurality of connecting hardware components, comprised of embedded female members mating with external male members, the male members extending between two adjacent panels, thereby coupling panels (a) in side-by-side relationship, and (b) in stacked configuration whereby said bottom horizontal edge of an upper-level panel is contiguous to said top horizontal edge of a lower-level panel, stacked upon a lowest level panel, wherein said embedded female members are proximal to a side edge; mounting means comprising external slotted angle brackets, each with a vertical arm and an horizontal arm, the vertical arm coupled to an embedded female member proximal to the bottom edge of a lowest level panel, and the horizontal arm is affixed to the foundation with a threaded concrete anchor bolt; each embedded female member comprises a bracket fitted with (a) a female connector extending outward from, and (b) tabs having orifices extending into, said inner body, said orifices being passages for the reinforcing rods of the grid, and wherein each external male member comprises a bracket fitted with male connectors mating with a female connectors of adjacent panels, said embedded female members being proximal to an edge of each panel; each said bracket having a slot in which one said connector is movably mounted, a bracket for a female connector having an horizontal slot and the male connector mating therewith mounted in a vertical slot; alternatively, the bracket for a female connector has a vertical slot and the male connector mating therewith is mounted in an horizontal slot; whereby two degrees of freedom are provided to achieve optimum alignment of adjoining panels; a similar panel for coupling to an adjacent panel at an angle less than 180° to form a vertical corner, wherein said external male member is comprised of an angle bracket, and said embedded female member is spaced from one said side edge so as to permit the inner face of the similar panel to overlap the adjacent side edge of the adjacent panel; paired male and female components for connecting each said panel in adjustable spaced apart relationship to said framework, each female component being embedded in a panel and each male component projecting from said framework; and wherein the exposed external hardware components extend from the inner faces of said panels, so that said outer faces of the assembly of panels presents a smooth, continuous exterior curtain-wall surface over the building skeleton. 